scholarly journals Cytokinin-Facilitated Plant Regeneration of Three Brachystelma Species with Different Conservation Status

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1657
Author(s):  
Nqobile P. Hlophe ◽  
Adeyemi O. Aremu ◽  
Karel Doležal ◽  
Johannes Van Staden ◽  
Jeffrey F. Finnie

In Africa and Asia, members of the genus Brachystelma are well-known for their diverse uses, especially their medicinal and nutritional values. However, the use of many Brachystelma species as a valuable resource is generally accompanied by the concern of over-exploitation attributed to their slow growth and general small size. The aim of the current study was to establish efficient micropropagation protocols for three Brachystelma species, namely Brachystelma ngomense (endangered), Brachystelma pulchellum (vulnerable) and Brachystelma pygmaeum (least concern), as a means of ensuring their conservation and survival. This was achieved using nodal segments (~10 mm in length) as the source of explants in the presence of different concentrations of three cytokinins (CK) namely N6-benzyladenine (BA), isopentenyladenine (iP) and meta-topolin riboside (mTR), over a period of 6 weeks. The highest (25 µM) concentration of cytokinin treatments typically resulted in significantly higher shoot proliferation. However, each species differed in its response to specific CK: the optimal concentrations were 25 µM mTR, 25 µM iP and 25 µM BA for Brachystelma ngomense, Brachystelma pulchellum and Brachystelma pygmaeum, respectively. During the in vitro propagation, both Brachystelma ngomense and Brachystelma pygmaeum rooted poorly while regenerated Brachystelma pulchellum generally lacked roots regardless of the CK treatments. Following pulsing (dipping) treatment of in vitro-regenerated shoots with indole-3-butyric acid (IBA), acclimatization of all three Brachystelma species remained extremely limited due to poor rooting ex vitro. To the best of our knowledge, the current protocols provide the first successful report for these Brachystelma species. However, further research remains essential to enhance the efficiency of the devised protocol.

2007 ◽  
Vol 8 (1) ◽  
pp. 22 ◽  
Author(s):  
Fabiola Ocampo ◽  
Víctor Manuel Núñez

<p>Se indujeron múltiples brotes mediante organogénesis directa a partir de segmentos nodales de 10 genotipos diferentes de guayaba. Para ello se estableció un sistema de propagación clonal <em>in vitro </em>combinado con inducción rápida de brotes <em>ex vitro </em>para propagar árboles élite. La utilización de segmentos nodales permitió obtener en poco tiempo brotes adventicios adecuados para multiplicación masiva. La respuesta <em>in vitro </em>de los genotipos fue evaluada usando los medios de cultivo MS (Murashige y Skoog, 1962), Mc (Mascarenhas) y WPM (<em>Woody Plant Medium</em>) suplementados con 0,1 mg•L-1 de ácido indolácetico (AIA) y 0,25 mg•L<sup>-1</sup> de bencilaminopurina (BAP). El procedimiento de desinfección con hipoclorito de sodio previno eficientemente la contaminación de los explantes después de la inoculación en el medio de cultivo. El mayor porcentaje en la inducción de brotes se logró con 0,25 mg•L<sup>-1</sup> de BAP. Los segmentos nodales presentaron de 1 a 2 brotes adventicios por explante después de 15 días de inoculados y de 3 a 7 brotes a los 30 días después del inicio del cultivo. Una vez individualizados los brotes se usaron en una nueva fase de multiplicación masiva en la que se probaron cuatro sustratos diferentes durante el enraizamiento y el endurecimiento. Esta metodología permitió la propagación <em>in vitro </em>de guayaba cuatro semanas después del inicio del cultivo. Los mejores resultados se lograron con el medio WPM que permitió obtener las primeras plántulas enraizadas dos semanas después de la transferencia al sustrato de enraizamiento.</p><p> </p><p><strong>In vitro propagation of Psidium guajaba using direct organogenesis from nodal segments</strong></p><p>Multiple shoots were induced using direct organogenesis from nodal segments of 10 different genotypes of guayaba. For this an in vitro clonal propagation system combined with rapid ex vitro induction of shoots was established in order to propagate elite trees. The use of nodal segments resulted in adventitious shoots adequate for mass multiplication in less time. The in vitro response of the genotypes was evaluated using the culture media MS (Murashige and Skoog, 1962), Mc (Mascarenhas) and WPM (Woody Plant Medium) supplemented with 0.1 mg·L-1 of indole acetic acid (IAA) and 0.25 mg·L-1 of benzoaminopurine (BAP). The procedure for sterilizing with sodium hypochlorite effectively prevented the contamination of the explants after the inoculation of the culture medium. The greatest percentage of shoot induction was achieved with 0.25 mg·L-1 of BAP. The nodal segments showed between 1-2 adventitious shoots per explant 15 days post-inoculation and 3-7 shoots 30 days post-inoculation. Once individualized, the shoots were used in a new mass multiplication phase in which four different substrates were tested during rooting and hardening. This methodology permitted the in vitro propagation of guayaba four weeks post-inoculation. The best results were achieved with the WPM medium that resulted in the first rooted plantlets two weeks after the transfer to the rooting substrate.</p>


2012 ◽  
Vol 49 (No. 12) ◽  
pp. 537-543 ◽  
Author(s):  
V. Chalupa

In vitro propagation of Tilia platyphyllos Scop. has been achieved by axillary shoot proliferation and somatic embryo-<br />genesis. The influence of tree age, explant source, genotype, and phytohormones on micropropagation of juvenile and mature trees of Tilia platyphyllos has been investigated. Nodal segments and shoot tips were used as initial explants for axillary shoot proliferation. Low concentration of cytokinin (BA, BPA, TDZ) plus auxin (IBA) stimulated fast shoot multiplication. Microshoots<br />excised from proliferating cultures were rooted on low salt medium and produced trees were planted in the field. Embryo-<br />genic tissues were initiated from zygotic embryos cultured on MS medium supplemented with 2,4-D. After transfer of&nbsp; embryogenic tissues with developing embryoids on media lacking 2,4-D and supplemented with low concetration of IBA, the development of somatic embryos was enhanced. Secondary somatic embryogenesis led to the formation of new adventive somatic embryos. Trees produced from somatic embryos were planted in the field and exhibited normal growth and morphology.


2021 ◽  
Vol 39 ◽  
pp. 03002
Author(s):  
Gayane Melyan ◽  
Andranik Barsegyan ◽  
Narek Sahakyan ◽  
Kima Dangyan ◽  
Yuri Martirosyan

Optimization of in vitro culture conditions of grapevine phylloxera-resistant rootstock cultivar ‘Ruggeri-140’(Vitisberlandieri x Vitisrupestris) was carried out. Among the different sterilization treatments, maximum aseptic cultures were obtained for both explants apical tips and nodal segments when treated with Ca(ClO)2 at concentration of 1.5 % for 10 minutes plus 70 % ethanol for 30 s (T7). The maximum shoot proliferation was observed both in apical and nodal meristems cultured on MS medium supplemented with 1.0 mg/l BAP. MS/2 medium containing 1.0 mg/l indole-3-butric acid (IBA) gave the highest rooting percentage (100%) with the highest mean number and length of roots. The ex vitro survival of rooted micro shoots was 75.0%.


2018 ◽  
Vol 77 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Mahipal S. Shekhawat ◽  
M. Manokari

AbstractHybanthus enneaspermusis a rare medicinal plant. We defined a protocol for micropropagation,ex vitrorooting of cloned shoots and their acclimatization. Surface-sterilized nodal segments were cultured on Murashige and Skoog (MS) medium with different concentrations of 6-benzylaminopurine (BAP) and kinetin (Kin). Medium supplemented with 1.5 mg L−1BAP was found optimum for shoot induction from the explants and 6.4±0.69 shoots were regenerated from each node with 97% response. Shoots were further proliferated maximally (228±10.3 shoots per culture bottle with 7.5±0.43 cm length) on MS medium augmented with 1.0 mg L−1each of BAP and Kin within 4–5 weeks. The shoots were rootedin vitroon half strength MS medium containing 2.0 mg L−1indole-3 butyric acid (IBA). The cloned shoots were pulse-treated with 300 mg L–1 of IBA and cultured on soilrite® in a greenhouse. About 96% of the IBA-pulsed shoots rootedex vitroin soilrite®, each shoot producing 12.5±0.54 roots with 5.1±0.62 cm length. Theex vitrorooted plantlets showed a better rate of survival (92%) in a field study thanin vitrorooted plantlets (86%). A comparative foliar micromorphological study ofH. enneaspermuswas conducted to understand the micromorphological changes during plant developmental processes fromin vitrotoin vivoconditions in terms of variations in stomata, vein structures and spacing, and trichomes. This is the first report onex vitrorooting inH. enneaspermusand the protocol can be exploited for conservation and large-scale propagation of this rare and medicinally important plant.


2015 ◽  
Vol 20 (3) ◽  
pp. 498-517
Author(s):  
Huda ElGwedy ◽  
Ali Abido ◽  
Mohamed ElTorky ◽  
Bothina Weheda ◽  
Moahmed Gaber

2017 ◽  
Vol 45 (2) ◽  
pp. 383-391 ◽  
Author(s):  
Constantinos SALIS ◽  
Ioannis E. PAPADAKIS ◽  
Spyridon KINTZIOS ◽  
Marianna HAGIDIMITRIOU

The behavior of six citrus rootstocks, Volkameriana, Citrumelo ‘Swingle’, Citrange ‘Carrizo’, Poncirus trifoliata ‘Serra’, Poncirus trifoliata ‘Rubidoux’ and Poncirus trifoliata ‘Flying Dragon’, in in vitro propagation was studied and compared for shoot proliferation and rooting. In addition, the genetic relationships among the rootstocks studied and other Citrus species, using the Inter-Simple Sequence Repeats (ISSR) molecular markers, were investigated. Nodal explants of three months old shoots were used in Murashige and Skoog medium supplemented with N6-benzyladenine (BA) for shoot proliferation and with naphthaleneacetic acid (NAA) for rooting. The rootstock Volkameriana showed a statistically significant higher number of shoots (1.81), shoot length (15.14 mm) and number of leaves per explant (5.81), while all three Poncirus trifoliata rootstocks showed the lowest numbers. The number of roots and root length per explant were evaluated at the end of the rooting phase. The rootstock ‘Swingle’ showed a higher number of roots per explant (4.2) followed by ‘Flying Dragon’ (3.93) and ‘Carrizo’ (3.23) rootstocks. The rootstocks ‘Swingle’ (140.8 mm), Volkameriana (148 mm) and ‘Flying Dragon’ (131.12 mm) had significantly higher root length per explant compared to ‘Carrizo’ (31 mm) and ‘Rubidoux’ (34.5 mm). The ISSR molecular marker technique used in the present study grouped successfully the different species, varieties and rootstocks studied, revealing their genetic variability. The genetic variability observed among the rootstocks ranged between 0.29 (Poncirus trifoliata ‘Serra’ and Citrumelo ‘Swingle’) and 0.60 (Volkameriana and Citrumelo ‘Swingle’). The response of the rootstocks studied in in vitro propagation however is not related to their genetic affinity.


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